Spring-bed



UNITED sTATEs PATENT oEEicE.

JOHN H. CRANE, OF CHARLESTOIVN, MASSACHUSETTS.

SPRING-BED.

Speccaton forming part of Letters Patent No. 27,700, dated April 3, 1860; Reissued J' une 9,1863,

To all whom 'it may concern:

Be it known that I, JOHN H. CRANE, of Charlestown, in MiddleseX county, in the State of Massachusetts, vhave invented certain new and useful Improvements in Spring Foundations for Beds, Sofas, Chairs, &c.; and I do hereby declare that the following, taken in connection with the drawings that accompany and form part of this specification, is a description thereof so full and exact as to enable those skilled in the art to practice my invention.

The object of my invention is to produce a spring slat bed with the smallest possible number of joints and parts in such a manner that it shall be free, frictionless, and noiseless in its action, and also to provide for conveniently varying the width of the bed foundation, to suit the width of mattresses so that a neat and square edged bed can always be made.

My invention consists in the peculiar form of the springs which I employ together with their position and connection relating to the slats and to the rails of the frame with which the springs are connected, and in the peculiar form and arrangement of the said rails.

Figure l, of the drawings is a plan of a bed foundation embodying my invention. Fig. 2, a sectional view of the same, showing the springs in their relation to the slats and rail when free from pressure, and Fig. 3, is a sectional view, showing the relative position of the parts under pressure or load.

Inspection of the drawings will show that the rails (a) to which the springs (b) are connected are trapezoidal in section, with one side (c) at or nearly at right angles with the parallel sides of the rail, and that their sides (c) are the inner sides of the frame and adjacentto the ends of the slats. The other sides of the rails (c), as will clearly appear in the drawing, form such an angle with the other sides as to dove-tail or lock the rails (a) to the rails (c) in which grooves or mortices are formed corresponding to the section of (c) so that without any other fastening the rail (a) will not be moved from their normal position by any weight which may be placed upon the slats The form of the springs is such that when secured in their places on the upper side of (a) they curve downward,

at an angle with the faces (c) of the rails W w t and at a little distance therefrom (for a reason hereinafter set forth) and then turn upward terminating where connected to the slats at or a little above the upper face of rails (a). The springs (b) are riveted to the slats in the other ends of the springs are formed openings of such form as first to admit the passage of the screen heads (g) and then to prevent the accidental disengagement of the springs from the screws. The springs are so fastened to the slats that when they are detached from the frame the distance apart of the holes in the springs is less than that of the screws in the latter which renders it necessary to strain the slats and springs endwise to connect them with the rails, so that the springs and slats strain upon the frame, somewhat in the manner of the strings of a piano-forte, and hold the rails (a) in the posit-ion in which they are placed relative to the rails (c), which could not be done if the springs did not, by virtue of their peculiar form, admit of longitudinal as well as of vertical movement.

As the slats are depressed by load upon them the part of the springs riveted to the slats straightens, and but for the angular form of the springs near the sides (c) of the rails (a) would require a link connection involving joints, or else some provision for a sliding movement, which would create friction and be noisy, to allow of the endwise movement of the springs. But the form of my springs admits their noiseless, frictionless, endwise movement toward sides (c) without involving the use of any links, joints, or sliding of one part upon another.

The peculiar form and arrangement of my springs, relative to the rails (a) and slats (f), gives a degree of stability to the slats which does not to my knowledge exist in other inventions of the same class, and which enables me to dispense with such straps as unite the slats which are found in some spring bed foundations. I account for this peculiar stability of my slats as follows: The end of each of my springs which is not rigidly secured is that of the part of each spring which receives tensile strain from load upon (f), while the other part of the spring which is compressed by the same load is that riveted to the slat. The difference in the stability between slats superincumbent on an unfiXed end of a spring, or pendent from such an end is With Which the Width of the bed frame can be made to conform to any given Width of mattress, and the ease With which the parts can be detached from each other for cleaning'and transportation, its simp1icity,rcheap ness, and noiseless action.

Having described my invention, what I claim and desire to secure by Letters Patent of the United States is- The combination and arrangement substantially as specified of the springs (b), slats (f), and adjustable frame (a e).

J OHN H. CRANE.

Witnesses:

J. B. CROSBY, GORDON MCKAY. 

